Mechanical time-fuse.



H. PRAHL.

` MECHANICAL TIME FUSE. APPLICATION FILED FEB. e, I9I5.

lma I Patented :Ian.30,1917.

www ww. im amg *estaran strains r 'HUG-0 PRAHL, OE DUSSELDORF, GERMANY, ASSIGNOR TO RHEINISCHE METALL- WAEEN- UND MASCHINENFABRIK, 0F DUSSELDORFDERENDORF, GERMANY,

il. CORPORATION OF GERMANY.

MECHANICAL sinn-FUSE'.

imanes.

Specification of Letters Patent.

y Patented Jan. 3' 1917.

To all 'whom t may concern:

Be it known that I, HUGO PRAHL, engineer, a subject of the German Emperor, residing at 7 9 Verdingerstrasse, Dusseldorf, Germany, have invented certain new and useful Improvements in Mechanical Timeing to. be a full, clear, and exact descrip'I 'tion of' the invention, such as will enable others sirilled in the art to which it appertains to malte and use the same.

My invention relates to improvements in mechanical time fuses having a clock-Work driven by a spring. In such fuses as heretofore known the driving spring has generally been constructedgas a spiral spring. Such springs are subject to the iniuence of centrifugal force during AHight of the pro'- jectile, and they require a large amount of space because of the length o r diameter rey quired tol give the necessary -power to the spring.

According to my invention the'influence of centrifugal force is overcome by the use et a plurality of helical springs arranged in Ior nearly in the axis of the shell7 such springsbeing cylindrical, conical, or of any .other suitable' form. I prefer to use a plurality of such helical springs and to arrange them conaxially, one within the other,

suchf arrangement requiring but a small amount .of space. further advantage ot my invention is L the aosence of friction between the single ivind-ingsof the spring, unnecessary.

Xn embodiment of my invention is shown in the accompanying drawings in' which- Figure l is an axial section through a fuse provided with a spring according to'my invention but showing only the essential parts necessary for understanding /iny invention. 2 is a cross section on line 2 2 of making lubrication l. Fig. 3 is an enlarged side view of.

the spring. lFig. 4 is a plan View of the same and Fig. 5 is a sectlon on line 5 5 of Fig. 4.

As stated the clock Work of the time fuse is not completely shown in Figs.' l* and 2, because this 1s not necessary foie understanding the invention.

Thedriving spring e is arranged the l axis of the rotation of theshell. As' shown f i conaxially one within the other. Fuses; and I do hereby declare the'followby Figs. 3, 4 and 5 the spring consists of a single Wire bent to form two oppositely Wound spaced apart coils,A one Within the other, the two coils having a common axis so as to form indeed two springs arranged evident that instead of a single Wire the springs may be spirally formed and then connected. It is also manifest that the spring may have the shape ot' a truncated cone or of a cask.

The spring is fastened with its end n to the shaft f of the driving wheel and with its other end m. to the winding up Wheel It.

The latter is connected with the shaft fv by means of any known regulation device which has for its purpose to allow the spring to be Wound up only for a limited number` of revolutions and further to .allow the It is selfranged on the Winding up Wheel 7c and.

adapted to engage an arm or pin of the driving shaft f' will he sul'licient for the said purpose.

The spring niay be of any cross section and made of any material. It may consist of one or several pieces.

That I claim is: In a mechanical time fuse having clockwork mechanism,` al driving spring for said mechanism comprising spaced apart oppositely wound convolutions arranged conaxially with respect to each other and to the axis of rotation of the projectile.

In testimony whereof, I have signed this speciiication` `in ,the presence of two subscribing Witnesses. j

HUGO 'PRAHL [12.5.] Witnesses HELEN hieran, ALBERT Nunn'. 

